1. Field of the Invention
The present invention relates generally to a computer mouse and, more specifically, to an ergonomic mouse for inhibiting repetitive stress injury.
2. Description of the Related Art
Repetitive stress injury (RSI) to computer users is the fastest growing form of workplace injury. Although RSI is not yet well-understood, it is known that RSI occurs from repeated physical movements of body parts, especially the wrists, hands and arms. A common type of RSI that occurs in the wrists is known as Carpal Tunnel Syndrome. Typing on a keyboard and using a computer mouse are potential sources of RSI. A mouse is a well-known input device that a user slides across a table surface such as a desktop to provide position data to a computer via a sensor in the mouse. A pad may be placed on the table surface to provide a more uniform surface on which to slide the mouse. A mouse typically also includes one or more finger-operated button switches for providing additional input. A user generally places his or her hand on the upper surface of the mouse and either rests it on the mouse or lightly grasps the mouse. The user's repetitive movements of activating the button switches and sliding the mouse may place stress on the wrist and hand ligaments and tendons.
A conventional mouse has a housing that slopes at its proximal end or end closest to the user's body. At the time such a mouse was first developed, this sloped housing design was apparently thought to be the most comfortable design for the user, but practitioners in the art have more recently come to believe that it promotes RSI. The sloping promotes a drooping of the wrist-end of the hand toward the table surface, causing an extension of the palm-side carpal ligaments, which is believed to stress them. To the extent that this drooped hand posture contracts the upper hand ligaments and tendons, they may be stressed as well.
Others have enhanced the computer mouse with so-called "ergonomic" mouse pads that have a wrist-supporting pad. Although such a mouse pad may inhibit the undesirable drooped hand posture, it may stress ligaments and tendons in the forearm when a user is reaching forward to position the mouse further from his or her body because the forearm rests on the pad intended to support the wrist. Furthermore, a user's watch band or bracelet pressed into the user's wrist or forearm by the wrist-supporting pad under the weight of the user's hand or forearm may increase stress to the ligaments and tendons.
Others have designed computer mice that position the user's hand in positions other than the substantially flat palm-down position, such as a "handshake" or "joystick" position thought by some to be more natural.
It would be desirable to provide an improved computer mouse that mitigates the possibility of RSI occurring. These problems are satisfied by the present invention in the manner described below.